POWER OF ATTORNEY

The undersigned, Andrew Larkin, does hereby make, constitute
 and appoint Howard C. Naphtali, P. Mats Goebels, Angelo
 Bulone, Saul P. Sarrett, Laurie Bennett, and Benjamin
 Reynolds, and each of them, true and lawful attomeys-in-
fact and agents with full power of substitution and
resubstitution, in any and all capacities, to execute for
and on behalf of the undersigned the reports and filings
required under Section 16 of the Securities Exchange Act of
1934, as amended (the "Exchange Act"), and the rules
promulgated thereunder (the "Section 16 Reports"), in
connection with transactions by and beneficial ownership
of the undersigned in securities issued by Investment
Technology Group, Inc. (the "Company"), and the Form 144
required under Rule 144 of the Securities Act of 1933, as
amended (the "Securities Act"), in connection with any sales
by the undersigned of securities issued by the Company, and
any other documents and instruments incidental to any of the
foregoing, granting unto said attomeys-in-fact and agents, and
each of them, full power and authority to do and perform
each and every act and thing that said attorneys-in-fact
and agents, and each of them, deem advisable or necessary,
including filing the Section 16 Reports, the Forms 144, and
amendments thereto with the Securities and Exchange Commission,
and the undersigned does hereby fully ratify and confirm all
that said attorneys-in-fact and agents, or any of them, or
their or his or her substitute or substitutes, shall do or
cause to be done by virtue hereof.

The undersigned acknowledges that the foregoing attorneys-
in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming,
any of the undersigned's responsibilities to comply with
Section 16 of the Exchange Act or Rule 144 of the Securities Act.

This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file the
Forms 144 or the Section 16 Reports with respect to the
undersigned's holdings of and transactions in securities
issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing
attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has subscribed
his name, this 12th   day of May, 2005.




___/s/ Andrew Larkin____

Andrew Larkin